Small FX loop for clones

[heisthl]

My weekend project - Using a 5x7x2 Hammond box with Fender stand-alone reverb Transformer and choke. I'll update when it's tested.
EDIT 12/17 updated attachment

[Normster]

That is SWEET!!! Keep us in the loop. (Sorry, I couldn't help it. )

[fabiomayo]

I don't even use effects loop, but you got me wanting one of those.

Pretty cool. Normster said right, keep us posted

All the best

[glasman]

FWIW, the two 10 meg resistors can be replaced with a single 22M. Also if space is an issue with the .22uf, a .1uf can also be subbed in that location. My less than dogears ( ) could not detect a dfference in performance.

Gary

[heisthl]

Well it works great - I made a couple of changes and re-posted the attachment in the top of the thread. Plates at 295 and 200. I'll post some pictures soon. The PITA on this one was I had to mount the board on the bottom cover which made for some longer leads than necessary. On the next one I'll rearrange a few on board components so I can cut a circle in the phenolic and mount the board around the tube socket which should result in very short leads.

[Robert]

Thanks for posting! That is the first layout with power supply I've seen for the Dumbleator. Several have suggested it improves the tone of the amps. What's your opinion?

I look forward to your pics.

[heisthl]

It does and it doesn't - the amp has to sound good or the loop won't do anything for it. The loop really doesn't distort much even on 10s with no external FX plugged in. What the loop does let you do is run more treble through the OD and smooth it back down which allows another variation in OD sound complexity. On the clean side a similiar effect takes place - that extra gain stage can give a little more sustain and rounder tone. Unless you have a really crappy effects unit I would doubt you ever need the bright switches.

[heisthl]

Here's some pics - before you groan at the long leads realize that this unit has 0 noise. I wouldn't do this again - instead I would redesign for an internally mounted board.

[fabiomayo]

Looks good. The size is really impressive.

[Tonegeek]

What tube are you using? thanks, whit

[heisthl]

Initially a 12AX7 but now I've been using a 12AT7 - I was worried about working the AX too hard on the first stage. The loop still has plenty of headroom with the AT - I suppose a 12AU7 would work well too or ideally a 12DW7 would give you the best of both worlds.

[JimiB]

what did you use for the choke?

[novosibir]

what did you use for the choke?

Fender 22707 - the Princeton/DeluxeRev choke.

Larry

[heisthl]

I should point out that since building this one I've learned that the V1a and V1b supply points should be swapped. The cathode follower side should be fed less voltage than the side with the 100k plate resistor. Also the 10k/1.5k string on the cathode should be raised to 27k/1.8k

[jelle]

'Also the 10k/1.5k string on the cathode should be raised to 27k/1.8k.'

Is this actual Dumbleator info? Or a member's tweak?
Jelle